Electrode or pencil for the arc-light.



i is tti lliD ISAJJUR LADOFF, OF CLEVELAND, OHIO, ASSIGNOR 0F THIRTYONE-HUNDBEDTHS T0 ZPHILIP C. "BECK, OF NEW YORK, N. Y,

ELECTRODE OR PENCIL FOR THE ARC-LIGHT.

i ,or noes.

No Drawing.

To all whom it may concern:

lie it known that l, l'sanou LAnorr, a citizrn of the Uni ed States, anda resident of the ity of Cleveland, county of Cuyahoga, and State orOhio, have invented certain n w and useful Improvements in Electrodes orl't-ncils For the Arc-Light, of which the foll wing is a specification.

the objcct of my present invention is to diminish the flickering of theare light from a metallic pencil, and, more particularly, to render itpossible to use in the production of such light: from such pencil by analternating current, and by such means as not to intertere'with theselective radiation peculiar to such pencil, my said invention he ingparticularly applicable to that class of metallic pencils which containtitanium.

l have discovered that undesirable flickering of the are light from suchpencils may be controlled, by supplying the arc with vapors having alower heat conductivity than those vapors resulting from thevaporization of the metal and particularly of titanium and some of itscompounds. To this end, i incorporate, with the pencil, any substance,or compound, capable of supplying the are with vapors having a lowerheat condiu-tivity than the vapors arising from the metal constituent ofthe pencil, and of such nature and in such quantity as not to intert'ere with the selective radiationof such metal, as, for instance,titanium.

My said invention may be applied as follows: 'lalcing, t'or instance, apencil composed of an alloy of titanium with another metalfsuch as iron,copper, etc., I add to the mixture of constituent ingredients of suchpencil, while in their powdered state, prior to molding, pressing andbaking, a certain proportion. say about. ten per centum of a substanceor c'omnound, volatile in the arc, preferably a salt of titanium, suchas potassiunntluotitanate (K 'lilfl) or sodium Specification of LettersItatent.

Patented Feb.i3, 1912.

Application filed may 1%, 1906. Serial No. 816,869.

fluotitanate (Na,TiF,,), or any other suitable substance or compoundpossessing the qualities aforesaid. The resulting pencils will give asteady arc, in an alternating cur-- rent, such are possessing thecharacteristic selective radiation of. titanium.

If preferred, the aforesaid added substance or compound may be suppliedto the metallic pencil as a core composed in whole or in part of suchsubstance or compound or in the form of an enveloping jacket surroundingthe pencil or in any other convenient manner, the essential being tosupply to the arc itself in sullicient quantities vapors possessing suchlow heat conductivity as to maintain. the arc during the intervalsbetween the opposite currents.

By means of my invention not only may metallic pencils be con'imcrciallyoperated with an alternating current but also the steadiness of theirare increased when used with a direct current. v

My invention may be also realized, though less perfectly, by combiningin the lamp with one metallic pencil another pencil adapted to producein the are said vapors the heat conductivity of which is lower than thatresulting from the metallic constituents of the pencils, as, forinstance, by combining in the lamp a term-titanium pencil with a carbonpencil.

Having thus described my invention, what I claim as new and desire tosecure by Let.- ters Patent is the following, vim- 1. An are light;pencil oon'iposed of an alloy of titanium with other metal and potassiumtiuotitauate.

2. An are light pencil composed ot an alloy of titanium with othermetal. and fluotitanatie of an alkaline metal.

15A IJOR LADOFF.

\Vitnesses \"V.-\i.'rnu l). linnosns, Puimr (l. lecit.

